Operation CHARM: Car repair manuals for everyone.

A056









Circuit Description
This DTC identifies a motor that cannot be energized due to an open in its circuitry. This malfunction will not allow proper front ABS operation.

Failure Condition
DTC A056 can be set only when the motor is commanded "OFF." If the EBCM detects an out of range voltage in either of the left front motor circuits indicating an open circuit, a malfunction exists.

Action Taken
An open motor will not activate when requested. A malfunction DTC is stored, ABS is disabled and the ABS indicator lamp is turned "ON."

Test Description
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step checks for proper resistance of the motor.
2. This step is used to release the tension of the motor pack prior to removal.
3. This step checks for an open in the motor "high" circuitry.
4. This step checks for an open in the motor "low" circuitry.

Diagnostic Aids
Using Tech 1, select manual control function, and exercise motor movement of affected channel in both directions while applying light pressure on the brake pedal.

If erratic or "jumpy" brake pedal movement is detected while performing an "apply" or "release" function of the motor, an intermittent malfunction may be indicated.

An "Intermittent" malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

If the malfunction is not current, wiggle the wires of the affected channel and check if the DTC resets. This will help to pinpoint an intermittent malfunction in the motor circuitry or connections.

The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.